1. Field
The present invention relates to an inkjet head that has nozzles for jetting ink drops, pressure chambers coupled to the nozzles, and actuators selectively applying a jetting pressure to the ink in the pressure chambers, and performs recording by using pigmented ink and dye ink.
2. Description of the Related Art
To meet recent demands for higher recording quality, there have been proposed inkjet heads which perform recording with pigmented ink and dye ink. In order to record high-quality images having high contrast, such proposed inkjet heads use a pigmented ink as black ink and use dye inks, which are vivid in color, as color inks other than black ink.
Because pigmented ink is less spreadable on a recording medium than dye ink, the volume of the ink drops of the pigmented ink jetted from the nozzles for recording one dot needs to be larger than that of the dye ink, to obtain the same resolution.
In such an inkjet recording apparatus, driving voltage waveforms of different pulse numbers may be used between when pigmented ink is jetted and when dye ink is jetted so that the number of drops of pigmented ink jetted for the recording of one dot is larger than that of the dye ink (See JP-A-2001-315324).
Apart from that, there has been proposed a method in which the length of the flow paths, from the pressure chambers to the nozzles, for the black ink is made different from that of the flow paths for the color inks, to thereby enlarge the drop gradation range.